USB: gadget: udc: fix wrong pointer passed to IS_ERR() and PTR_ERR()

IS_ERR() and PTR_ERR() use wrong pointer, it should be
udc->virt_addr, fix it.

Fixes: 1b9f35ad ("usb: gadget: udc: Add Synopsys UDC Platform driver")
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20210330130159.1051979-1-yangyingliang@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/snps_udc_plat.c

@@ -114,8 +114,8 @@ static int udc_plat_probe(struct platform_device *pdev)
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	udc->virt_addr = devm_ioremap_resource(dev, res);
-	if (IS_ERR(udc->regs))
-		return PTR_ERR(udc->regs);
+	if (IS_ERR(udc->virt_addr))
+		return PTR_ERR(udc->virt_addr);
 
 	/* udc csr registers base */
 	udc->csr = udc->virt_addr + UDC_CSR_ADDR;